FluidSynth Settings

The actual list of available settings, their options and min, max and default values will depend on build settings.

AUDIO DRIVER SETTINGS

audio.driver
String. ['pulseaudio', 'alsa', 'oss', 'coreaudio', 'dsound', 'portaudio', 'sndman', 'jack', 'file']. Name of the audio driver to use. Defaults to first available (built-in) driver from the list.
audio.periods
Integer. [min=2, max=64]. Number of periods tried by the alsa, oss, dsound and jack audio drivers. A warning will be shown when the actual value is different than the requested one. Default value is 8 for Windows and MacOS9, 16 for all other builds.
audio.period-size
Integer. [min=64, max=8192]. Period size tried by the pulseaudio, alsa, oss, dsound and jack audio drivers. A warning will be shown when the actual value is different than the requested one. Default value is 512 for Windows, 64 for all other builds.
audio.sample-format
String. ['16bits', 'float']. Sample format tried by the alsa, oss, dsound and jack audio drivers. Default value: '16bits'.
audio.input-channels
Integer. [min=0, max=2, def=0]. Obsolete.
audio.output-channels
Integer. [min=2, max=32, def=2]. Obsolete.

ALSA

audio.alsa.device
String. ALSA audio device name. Default value: 'default'.

JACK

audio.jack.autoconnect
Integer. [0, 1]. If equal to 1 then auto-connect audio output ports to the first physical input ports found. Default value: 0.
audio.jack.id
String. JACK identifier to use. Default value: 'fluidsynth'.
audio.jack.multi
String. ['no', 'yes']. If 'yes' then create separate output ports for reverb and chorus effects. There will be as many left/right port pairs as defined by "synth.audio-channels" + one left/right pair for reverb + one left/right pair for chorus effect. Default value: 'no'.

DSOUND

audio.dsound.device
String. DSound device name. Default value: 'default'.

OSS

audio.oss.device
String. OSS device name. Default value: '/dev/dsp'.

PULSEAUDIO

audio.pulseaudio.server
String. PulseAudio server. Default value: 'default'.
audio.pulseaudio.device
String. PulseAudio device name. Default value: 'default'.

PORTAUDIO

audio.portaudio.device
String. PortAudio device name. Default value: 'PortAudio Default'.

FILE

audio.file.name
String. File name where data will be written to. Default value: 'fluidsynth.raw'.

MIDI SETTINGS

midi.driver
String. ['alsa_seq', 'alsa_raw', 'oss', 'winmidi', 'midishare', 'coremidi']. Name of the MIDI driver to use. Defaults to first available (built-in) driver from the list excluding alsa_raw.

ALSA_SEQ

midi.alsa_seq.id
String. Client identifier, used to generate client and port names automatically. Default value: pid.
midi.alsa_seq.device
String. ALSA sequencer device name. Default value: 'default'.
midi.portname
String. MIDI client and port name. Default value: (automatically generated).

ALSA_RAW

midi.alsa.device
String. MIDI device name. Default value: 'default'.

OSS

midi.oss.device
String. OSS MIDI device name. Default value: '/dev/midi'.

WINMIDI

midi.winmidi.device
String. WinMIDI device name. Default value: 'default'.

COREMIDI

midi.coremidi.id
String. Client identifier, used to generate a distinguished client name automatically. Default value: pid.
midi.portname
String. MIDI port name. Default value: (automatically generated).

SYNTH SETTINGS

synth.reverb.active
String. ['yes', 'no']. When set to "yes" the reverb effects module is activated. Otherwise, no reverb will be added to the output signal. Note that when the reverb module is active, the amount of signal send to the reverb module depends on the "reverb send" generator defined in the SoundFont. Default value: 'yes'.
synth.chorus.active
String. ['yes', 'no']. When set to "yes" the chorus effects module is activated. Otherwise, no chorus will be added to the output signal. Note that when the reverb module is active, the amount of signal send to the chorus module depends on the "chorus send" generator defined in the SoundFont. Default value: 'yes'.
synth.ladspa.active
String. ['no', 'yes']. When set to "yes" the LADSPA subsystem will be called. This subsystem allows to load and interconnect LADSPA plugins. The output of the synthesizer is processed by the LADSPA subsystem. Note that the synthesizer has to be compiled with LADSPA support. Currently disabled because of some stability issues. Default value: 'no'.
synth.midi-channels
Integer. [min=16, max=256]. This setting defines the number of MIDI channels of the synthesizer. The MIDI standard defines 16 channels, so most hardware keyboards are limited to 16. If you plan to use the synthesizer as a plugin in an application, it might be interesting to set the number of channels to a larger value. In this case you can program a greater number of presets. One MIDI port is created for every 16 channels. Default value: 16.
synth.polyphony
Integer. [min=16, max=4096]. The polyphony defines how many voices can be played in parallel. The number of voices is not necessarily equivalent to the number of notes played simultaniously. Indeed, when a note is struck on a specific MIDI channel, the preset on that channel may created several voices, for example, one for the left audio channel and one for the right audio channels. The number of voices activated depends on the number of instrument zones that fall in the correspond to the velocity and key of the played note. Default value: 256.
synth.sample-rate
Float. [min=22050.000, max=96000.000]. The sample rate of the audio generated by the synthesizer. The audio driver will try to use the same sample rate, but when not possible it will just show a warning and continue with not matching sample rates. Default value: 44100.000.
synth.verbose
String. ['no', 'yes']. When set to "yes" the synthesizer will print out information about the received MIDI events to the stdout. This can be helpful for debugging. This setting can not be changed after the synthesizer has started. Default value: 'no'.
synth.gain
Float. [min=0.000, max=10.000]. The gain is applied to the final or master output of the synthesizer. It is set to a low value by default to avoid the saturation of the output when random MIDI files are played. Default value: 0.200.
synth.audio-channels
Integer. [min=1, max=256]. By default, the synthesizer outputs a single stereo signal. Using this option, the synthesizer can output multichannel audio. Number of left/right output pairs when "audio.jack.multi" is enabled. There's a practical limit of 128 channels in the source code (FIXME). Default value: 1.
synth.audio-groups
Integer. [min=1, max=256]. By default, the synthesizer outputs a single stereo signal. Using this option, the synthesizer can output multichannel audio. This value should be the same as "synth.audio-channels" unless LADSPA is enabled, then it will be the number of inputs to the LADSPA subsystem. There's a practical limit of 128 groups in the source code (FIXME). Default value: 1.
synth.effects-channels
Integer. [min=2, max=2]. Obsolete.
synth.dump
String. ['no', 'yes']. Obsolete.

SHELL SETTINGS

shell.port
Integer. [min=1, max=65535]. Port used in server mode (not working for Windows, see "defect: Server mode not working on Windows (new)">#20). Default value: 9800.
shell.prompt
String. Prompt to use by the shell. Default value: .